A New Digester OR ENGINE FOR SOFTNING BONES CONTAINING THE DESCRIPTION Of its Make and Use in these Particulars VIZ. Cookery Voyages at Sea Confectionary Making of Drinks Chymistry and Dying WITH AN Account of the Price a good big Engine will cost and of the Profit it will afford By DENYS PAPIN M.D. Fellow of the ROYAL SOCIETY LONDON Printed by J. M. for Henry Bonwicke at the Red Lyon in S. Paul's Church yard 1681. At a Meeting of the Council of the Royal Society Decemb. 8th 1680. ORdered That a Book intituled A New Digester or Engine for softning Bones c. Written by Denys Papin Doctor of Physick and Fellow of this Society be Printed and Published Chr. Wren TO THE MOST ILLUSTRIOUS THE ROYAL SOCIETY Most Honoured Sirs THE favourable Acceptance you give to all those who according to your Institution are studious to increase both Natural Knowledge and the Commodities of Humane Life hath encouraged me to present you with these Experiments as my best Endeavours to follow your Example I confess they are nothing near deserving to be offered to such sagacious Wits but I have seen how quickly and easily you distinguish between good and bad in all manner of Writings and how kindly you bear with the defects of those whose designs are good I hope therefore you will be pleased to honour this small Treatise with your Protection and give me leave to profess my self with all imaginable Respect Most Honoured SIRs Your most humble and most obedient Servant D. PAPIN PREFACE SOme Experiments of the screwed Balneum Mariae have already been printed in the second continuation of the Physico-mechanical Experiments of the Honourable R. Boyle put forth this year 1680. but that Book being writ in Latine and not giving the Description of the Engine nor the ways how to use it safely for want of sufficient Tryals I thought it would not be improper now to make upon that Subject a separate Treatise in the vulgar Tongue for the use of such House-keepers and Tradesmen as may have occasion for it Having therefore reason to believe that this Piece may fall into the hands of divers persons that would never read the History of the Royal Society nor Mr. Boyle's Book about the Usefulness of Experimental Philosophy I thought this to be a very fit place to undeceive those that imagine it to be a folly to look for new Discoveries and that all things are already found out For the confuting this errour I will take nothing but from my subject and even amongst several instances it affords I will use but one Therefore I shall only say that Cookery is such an ancient Art the use whereof is so general and so frequent and people have been so earnest upon the improving of it that it seems if any could be brought to perfection this should be it nevertheless no body can deny but it will be now considerably improved seeing by the help of the Engine here treated of the oldest and hardest Cow-Beef may be made as tender and as savoury as young and choice meat I may besides say that this was no hard matter for every one knows that compact Bodies if hot will burn more powerfully than those of a more rare contexture That red-hot Iron for example will do more than Coals so there was no question but that water being heated enough for boiling and shut up so as not to be able to expand it self as by ebullition it doth such water I say would effect much more than if permitted to its ordinary boiling expansion For my part assoon as this came into my mind by making some Experiments about Compression for Mr. Boyle I thought it so certain that I made no question to undertake that Tryal yet though the thing was so easie no body that I know of had any thoughts of it many Learned men have done and do still things of much more difficulty but no body can see all things Therefore we must confess that there may still remain Discoveries to be made by small as well as great Capacities And no man that industriously prosecutes a Subject though seemingly never so trivial need despair of obtaining that great felicity of having made some Discovery the usefulness whereof may recommend it to Posterity INDEX HOW to know the quantity of pressure in the Digester Pag. 2 How to know the degree of heat Pag. 4 Meat may be kept upon the fire three times as long as is necessary to make it ready and yet it will not be spoiled Pag. 9 10 The same Experiment made upon Bones Pag. 11 How to boil Mutton Pag. 8 How to boil Beef Pag. 9 How to boil Lamb Pag. 13 How to boil Rabbets Pag. 15 How to boil Pigeons ibid. How to boil Fish Pag. 17 How to boil Pulse Pag. 19 How to make Gelly very cheap Pag. 21 Glue for Glasses Pag. 25 Harts-horn turned like Parmezan Cheese Pag. 28 A Macquerel kept without Salt Pag. 29 Salt water as good for nourishment as fresh water Pag. 30 To make Sweet-meats at a cheap rate and of a new taste Pag. 32 33 34 To make two sorts of Drink with the same fruit Pag. 35 36 37 To make a new kind of Wine Pag. 37 Tinctures drawn in the hundredth part of the time usually required for them Pag. 39 New ways for Distilling Pag. 40 41 42 How to hatch Chickens Pag. 44 How to save the labour of grinding Cochenille Pag. 47 To dye with thick Juyees Pag. 48 To make Horn and Tortoise-shell soft for a great while Pag. 50 ERRATA Page 1. line 19. for GG read GG Fig. 2. p. 3. l. ◠for LG r. LQ p. 16. l. 32. for Exper. 3. r. Exper. 2. p. 20. l. 13. for Chap. 3. r. Chap 〈◊〉 p. 45. l. 3. for other glass r. Weather glass p. 48. l. 35. the paragraph to 〈◊〉 at Because and a comma after taste CHAP. I. The Description of the Engine and how to use it safely AA Is a Brass Cylinder hollow within shut up at the bottom and open at the top BB. Is another hollow Cylinder of the same bigness as the other but much shorter being to cover and shut the same by applying both their apertures to one another as you may see in the Scheme CC. Are two Appendices or Ears cast to the Cylinder AA as the Tronions of a piece of Ordnance DDDD Are two pieces of Iron put upon the Appendices CC. at one end and the Iron bar EE at the other EE Is an Iron bar put through the ends of the Iron pieces DD. and so may easily be taken off or put on when we have a mind either to open or to shut up the Engine FF Are two Screws which being sitted to the holes in the bar EE serve to press both the Cylinders AA BB. against one another GG Is another hollow Cylinder made of Glass Pewter or some other Material fit to receive those things that are to be boiled this being filled and stopt with a cover
Pigeons into two little Glass-pots weighing them one after another before I inclosed them in their frame I prest the fire till the drop of water would dry away in 5 seconds and the inward pressure was ten times as strong as the ordinary pressure of the Air. The Vessels being cooled I found both the covers sticking pretty fast to their Pots so that it was apparent that the Air within the said Pots was rarified and that something had got out of them I weighed them one after the other being well dried as I had done before the boiling and I found that one of them wherein I had put by weight an eighth part less of meat than the Vessel could contain of water was exactly the same weight as before and the bones were very tender and the Juyce a strong Gelly without Empyreume The other Pot wherein I had put a greater weight of meat than it could hold of water was grown heavier and the Juyce in it was not so well congealed as in the other It is very like that the great quantity of meat being too much rarified in this Pot had opened the cover so as to admit some of the water from the Balneum Mariae which had increased the weight and diluted the Gelly but in the first Pot the rarefaction of the meat was able only to drive out a little Air without any sensible opening of the cover From this Experiment I think we may conclude that one Propriety of this Engine is That if we boil Pigeons so as to make the drop of water dry away in 5 seconds with an inward pressure ten times as strong as the ordinary pressure of the Air the weight of the meat in the Pot must be but 〈◊〉 of that which the Pot can hold seven pounds of meat for example in a Pot that can hold eight pounds of water for by that means the pressure in the Pot is as strong as in the Engine and yet nothing is lost In the sixteenth Experiment you may see that the water being taken in the same weight would do the same effect so that some people would think that all other bodies should be also taken in the same weight because those that would take up less room upon the score of their specifick gravity will by the same reason expand themselves so much the more but this would be a great mistake for I have tryed Chap. 6. Exper. 3. that Spirit of Wine though of a lesser specifick gravity than Vinegar will nevertheless rarifie a great deal more by heat Therefore if we will be very exact not to lose any thing and to have the intended pressure in the Pot we must find by experience how far and how powerfully other bodies will rarifie as in this Experiment I have found it for Pigeons to fill afterwards the Pot accordingly At the same time I had in another Engine some of the same Pigeons a boiling the heat was such that it dryed a drop of water in 3 seconds but the inward pressure was but five times as strong as the ordinary pressure of the Air. The Vessels being cooled I found the bones not quite so soft as in the other Engine though they had been in a greater heat yet they were almost all fit to be eaten This Experiment makes me believe that we may reckon this amongst the Proprieties of this Engine That it is almost the same thing to have the drop of water dry away in 3 seconds and five pressures as to have it dry away in 5 seconds and ten pressures in the Engine So people may find out by experience in any other case what quantity of pressure may do instead of a certain quantity of heat and if one had an exact Thermometer as I have said in Chap. 2. one might perhaps draw from thence great lights for other things I say besides that this Experiment shews that good Balnea Mariae fitted to hold great pressures would save a great deal of fire for we have seen Exper. 10. that the greater the inward pressure is the less coals will serve to bring the Engine to a certain heat and now we see that such a degree of heat raised with less coals may produce a greater effect than if we had been forced to bestow more coals for it where this pressure is wanting FISH EXPERIM. XIII June 15. I took a Macquerel and put it in a Glass-pot with green Goosberries I included the Pot in the Engine and with four ounces and two drams of coals I brought the heat to dry away the drop of water in 10 seconds and the inward pressure was seven times as strong as the ordinary pressure of the Air. The fire being gone out by little and little I found that the remaining coals weighed about two drams the fish was very ready and firm though the bones were so soft as not to be felt in eating the fish before it was boiled did weigh nine ounces and after boiling not above seven so that I had two ounces of good Juyce which would have been thrown away if the fish had been boiled after the ordinary way and moreover the taste was a great deal better the volatile Salts not having got away or been dissolved in water the Goose-berries had a very good taste and nothing of burning EXPERIM. XIV June 19. I made the same tryal with a Pike and I gave the fire as in the former Experiment the fish was found very ready and its flesh firm and the bones soft though they seemed somewhat harder than those of the Macquerel A Gentleman having tasted of this inquired whether it was the dissolving of the bones that made the fish so savoury this perswaded me that my thinking such fish better than ordinary was not out of preoccupation The Juyce of the Pike came to a strong Gelly which did not happen to that of the Macquerel I cannot tell whether this difference proceeded from the nature of the fish or from the temperature of the Air. EXPERIM. XV. June 20. I took a great Eel and having shut it up as I use I kindled four ounces and half of coals so that the drop of water did dry away in 6 seconds and the inward pressure was seven times stronger than the ordinary pressure of the Air the fire being gone out of it self the Eel was found very ready so was the skin and bones and all without Empyreume but its flesh was not so firm as that of other fishes the juyce did not congeal which I think did proceed from the excess of fire rather than from the nature of this fish since its skin seems very fit to make Gelly All these Experiments make me believe that all fishes may be made ready almost with the same degree of heat PULSES EXPERIM. XVI July 2. I put Beans in a Glass-pot some of which were raw and the other had been boiled already with Harts-horn I poured a little water into the pot to see the difference between those Beans that would
Chap. 2. Exper. 13. so that their bones were soft then I left one dry in the open Air and having kept it for eight days though in very hot weather it was not corrupted at all but another piece which I kept in the sauce was corrupted before three days I had a mind to try afterwards whether an ordinary boiling would have the same effect and to that end June 26. I boiled a Macquerel after the ordinary way and having set it to dry as I had done with the other I found that it would stink in less than four days From this Experiment I believe it appears that this Engine would be useful to dry Victuals so as to keep them without Salt and without losing their juyce and it may be such Victuals will prove much more wholesom than salt Victuals that are so much used at Sea EXPERIM. X. This Engine being so useful to hinder the wasting of fresh water by evaporation I thought it might also in some cases make Sea-water serve instead of fresh water Having therefore dissolved one dram of Salt in forty drams of water which I have heard from Mr. Boyle to be much the same proportion of Salt as is in Sea-water I took an ounce of dry Pease and having put them in a glass-pot with double their weight of the said salt water I included them in the Engine I blew up the fire till the drop of water would evaporate in 4 seconds with an inward pressure ten times stronger than the ordinary pressure of the Air. The Vessels being cooled I found that the Pease had imbibed all the water and were very well softned and Dr. King having tasted the same found them very savoury and not too much salted it is very likely that Beans and all other Pulse will do the same I think therefore that in supplying a Ship with Victuals we may reckon that the Pulse will change double their weight of Sea-water into fresh water or at least make it serve for nourishment as well as if it had been fresh and this may diminish very much the quantity of fresh water Ships must be incumbred with If people should use Sea-water to boil Pease in after the ordinary way it would come to pass that the evaporation wasting but the watry parts would make the Pease exceeding salt and besides that they could never be well softned I did also try whether sea-Sea-water could be used to make Gellies therefore I put some of the same salt water into a pot with an equal weight of Mutton-bones and having increased the fire as I use to make Mutton-bones gelly I found a very strong gelly indeed but it was too salt by a great deal the quantity of congealing parts being so little that it cannot much contemperate the saltness of the water I think therefore that Sea-water should be mingled with double its weight of fresh water to make gelly withal CHAP. IV. Experiments for Confectioners EXPERIM. I. JVne 27. I put Cherries into two Pots in one of them there was water enough to cover the Fruit to the other I added nothing at all having forced the fire till the drop of water would dry away in 40 seconds with the inward pressure 3 times stronger than the ordinary pressure of the Air I found the Cherries very well boiled and those had much juyce where I had added no water those with water had much more liquor but their taste was more waterish The next day I put some of these Cherries to dry in the open Air and I put some also to boil again with Goose-berries to see whether a new boiling would spoil them I blew up the sire till the drop of water would dry away in 10 seconds with the inward pressure eight times stronger than the ordinary pressure of the Air and after that I did not find the Cherries at all altered but were still as big and as entire as before they had been boiled I put some of these also to dry in the open Air. The next day I found that all these Cherries would dry very well and not corrupt but those that had been boiled but once without water were bigger than all the rest and those that had been boiled twice were very wrinkled and grown smaller than the others that had been as long again a drying This Experiment shews that some Fruit may without danger remain a great while upon the fire in this Engine after they have been boiled enough and that makes them to be not so fit to corrupt as they were before therefore I believe if those who are skilful that way would make a Syrup to keep such Fruit in without drying they might have Sweet-meats which not having been boiled in Sugar would keep much better the taste of the Fruit but I think the Syrup should be thicker than usual because the moisture of the Fruit is apt in a little time to mingle with it and make it more liquid Experience must teach us what degree of heat will be the best to preserve Fruit without much altering its taste EXPERIM. II. July 6. I put into a pot sive ounces of Goose-berries and having continued the fire till the drop of water would dry away in 15 seconds I presently put it out The Vessels being cooled I found that the Goose-berries had yielded an ounce and half of liquor pretty thick I put some of these Goose-berries to dry in the open Air and they did dry very well and not corrupt This Experiment made me the more apt to believe that Sweet-meats might be so ordered as to keep much of the taste of the Fruit and I believe at the same time one might have a great conveniency to make clear Cakes because the juyce sit for that purpose is all kept in this Engine and may be drawn a great deal sooner than after the ordinary ways EXPERIM. III. July 22. Three weeks ago I shut up ripe Goose-berries in a great glass and put to them water satiated with Sugar to sill up the interstices to day seeing these Goose-berries ferment apace and make abundance of bubbles I put some of them in a glass-pot with some of their liquor and having inclosed it in the Engine I continued the fire till the drop of water did dry away in 6 seconds with an inward pressure five times stronger than the ordinary pressure of the Air. I took off the fire and the Vessels being cooled I found the Goose-berries very well boiled soft and of a good taste though the Fermentation had made them hard and unpleasant to the palate I included at the same time another pot full with fresh Goose-berries to which I added one part of Sugar to five parts of Fruit I found them also very ready and of a very pleasing taste but much more sweet than those that had been fermented After I had left these two glass-pots for ten days together well covered but not above â…“ full I saw no Fermentation in them but the Fruit grew a little musty
lesser at this time the meat was nevertheless much more burnt than the other because I believe I had blown the fire more briskly EXPERIM. III. June 6. I repeated the same Experiment and took but five ounces of coals and gave just heat enough to dry up the drop of water in 4 seconds the inward pressure as before then the Mutton was very well done the bones soft and the juyce a strong Gelly so that having had occasion to boil Mutton several times since I have always observed the same rule and never missed to have it in the same condition which I take to be the best of all because if the coction was lesser the bones could not be soft and if it was stronger the Gelly being softer could not be so nourishing Yet I do not think that the perfection in this case is limited to a little more or less but I believe rather that Mutton may be considerably more boiled and be very good still yet I had always rather to under-do it a little than over-do it because when it is over-done there is no remedy and if some pieces of bone be not soft enough it is very easie to put them again with new meat EXPERIM. IV. June 9. I made the Experiment with a Breast of Beef and took seven ounces of coals I urged the fire till one drop of water would dry up in 3 seconds and the inward pressure about nine times as strong as the ordinary pressure of the Air the coals that were not consumed did weigh about three quarters of an ounce and the Beef was very well boiled although there were some parts of the bones not quite softned yet I would not advise people to bestow any more fire to boil Beef because it is always very easie to boil the bones again and I had rather several times boil the meat but as much as may be necessary to take it off from the bones because afterwards the bones may without any danger be boiled asunder as you may see by the following Experiments EXPERIM. V. June 12. I did put Mutton and Beef together into my pot and made the fire but with three ounces of coals and though I prest the fire pretty briskly I could not make the inward pressure above three times stronger than the ordinary pressure of the Air and the heat but such as to make a drop of water to evaporate in 90 seconds The Vessels being cooled I found the Mutton ready enough to please most people but the Beef was undoubtedly too raw for any body the Juyce did not turn to a Gelly though I had put no water to it I believe that the pressure and the heat in this case were so little rather for want of having well fitted the Engine than for want of coals for I have observed since that time That the better the Engine is closed the more heat it acquireth with the same quantity of coals June 13. I repeated the same Experiment and filled the Pot partly with raw flesh and partly with some of the flesh boiled the day before I took but four ounces of coals and having increased the fire as briskly as I could I made the inward pressure but five times stronger than the ordinary pressure of the Air and the heat but such as to make a drop of water to evaporate in 40 seconds the coals that remained not consumed did not weigh above two drams the meat was very well done and tender but the bones did not at all seem softer than before although those of the day before had already endured the fire of seven ounces of coals three the first day and four the second June 15. I repeated the same Experiment and did put into the Pot the meat that had already been boiled twice and also raw flesh at which time I imployed five ounces of coals but I prest the fire so gently that the heat could never make a drop of water to evaporate in less than two minutes or 120 seconds The fire being gone out of it self I found the meat done enough and that which had endured the fire of twelve ounces of coals was very good still without Empyreume and the bones not at all softned So I found that it was very easie to dress flesh without bones since it may be left upon the fire three times as long as is necessary and yet it will not at all be spoiled EXPERIM. VI. June 16. I made the same tryal with bones and took those very bones that had been thrice boiled with the meat of the last Experiment these being put into a glass-pot with fat of Mutton alone that had been already boiled I shut them into the Engine then having made such a heat as to dry a drop of water in 4 seconds and the inward pressure nine times stronger than the ordinary pressure of the Air I did quickly put out all the fire and the bones were found very well softned I did again inclose the same bones in the same pot with the same fat of Mutton and added to them a new piece of bone that had never been boiled and having given the fire as before I found the new piece of bone well softned and all the rest still very good June 17. I did for the third time inclose the same bones in the same pot and again a new piece of bone quite raw and having given again the same heat I found the new piece of bone well softned and all the rest not at all impaired I repeated again the same Experiment with the same bones and the same fat of Mutton but at this time I made a stronger and longer fire and it fell out that the first bones were almost brought quite to a powder and smelt of burning yet the taste did not seem so unpleasing as when flesh is so burnt As for the fat it had no ill taste at all only it seemed to be a little softer than some of the same fat that had been boiled but once so I cannot tell whether by much boiling one may not make it change its nature but I am sure it would require more time than I can bestow The three first Coctions mentioned in this Experiment are sufficient to shew that bones as well as flesh may be boiled at least three times as long as there is need and yet they will be in no danger of burning so it is plain that the most careless and unexact persons will be able enough to boil them asunder Proprieties Before I proceed I must take notice that in the fifth Experiment some bones that had endured the fire of twelve ounces of coals were not at all softned to sense although five ounces of coals may be enough to produce that effect from whence it appears that the weighing of coals would signifie but little unless we did at the same time observe how briskly we augment the fire for there would be always danger of doing the meat more or less than we intend and we may
reckon this as a Propriety of this Engine That the more briskly we press the fire the more effect it produceth with the same quantity of coals This Experiment put me in mind to make another that might manifestly shew that the inward pressure is a great help to advance coction therefore I took two little Vessels very like one another and well fastned by Screws one of them was well soddered every where but the other had a little hole left in its cover for the vapors to get out These Vessels being filled with water and meat after the same manner and put together in the same Bath of Sand and left there in an equal heat for three quarters of an hour I took them off both together and found that the meat that had been exactly shut up was rather over than under done but the other was a great deal too raw therefore we may reckon this also amongst the Proprieties of this Engine That the greater the inward pressure is the greater effect is produced by the same heat and in the same time EXPERIM. VII Having found some difference between Beef and Mutton the one being harder to be boiled than the other I had a mind to see whether there would not be some difference also between flesh of the same kind but of different ages therefore June 4. I took Lamb and filled two Glasses with it and put some water into one of them Now since five ounces of coals have been enough to boil Mutton I took but four ounces and half for the Lamb thinking it would be more easie to be boiled I prest the fire as briskly as I could but a drop of water would not dry away in less than 11 or 12 seconds the inward pressure was eight times stronger than the ordinary pressure of the Air the heat was but so little which may be because the greater share of the coals had been once already kindled the fire being gone out by little and little I found but one dram of coals that had not been consumed In the Glass without water the bones were softned at some of the ends only but in the Glass with water the bones were all very soft yet the meat was much less savoury than in the other Vessel This Experiment caused me to think 1. That the bones of young beasts require almost as much fire as those of old ones to be boiled 2. That water is a dissolver fit to soften bones but that it impairs the taste EXPERIM. VIII Propriety That I might know pretty near what difference may be found as to the perfection of the Operation when the fire goes out of it self or when it is all taken off and quenched as soon as the heat is come to the intended degree July 5. I filled again two glass-pots with Lamb as before and having kindled a great deal of coals I prest the fire till a drop of water would dry away in 3 seconds and presently I took off all the fire I found the bones in the Pot without water a little softer than in the former Experiment and in the Pot with water I found them all very soft but the meat was not at all spoiled So I think it is near the same to press the fire with 4 ½ ounces of coals so as to dry away a drop of water in 10 seconds and then let the fire go out of it self or to press the fire with-six or seven ounces of coals and then take it all off as soon as a drop of water drys away in 3 seconds therefore the same proportion may be observed in other Operations For Example If I were to make an Operation that might be performed with a quantity of coals that could make the Engine hot enough to dry a drop of water in 20 seconds leaving afterwards the fire to go out of it self and if I would save time I should make a good fire that the heat might quickly come to dry a drop of water in 6 seconds and presently take away all the fire and so in all other Operations keeping still the proportion as 10 to 3 yet I confess this Rule is not demonstrated neither doth the matter in hand require such a Mathematical exactness When I say nothing of the inward pressure as in this Rule it is to be understood that it ought to be always equal EXPERIM. IX July 11. I took a Rabbet and having filled with it two Glass-pots and put some water in one and none in the other I kindled five ounces of coals and having prest the fire till a drop of water would dry away in 4 seconds I let the fire go out of it self The Vessels being cooled I found the Rabbets bones well softned in the Pot with water but in the other they were all very hard yet the flesh having been well seasoned it was as tender and savoury as any Pasty can be but in the Pot with water it relished not so well by a great deal By this Experiment I saw that Rabbets bones are harder than those of Mutton and I was more fully satisfied that water helps much the softning of bones EXPERIM. X. Propriety I took another Rabbet and having shut it up as in the former Experiment I kindled five ounces and half of coals but the paper in the joynt of it having been spoiled the inward pressure was not as strong again as the ordinary pressure of the Air because the water could get out and for that reason also the heat could not well be kept for notwithstanding the quantity of coals in this Experiment was greater the drop of water was twenty times longer evaporating than in the former Experiment So that we may reckon this for a Propriety of this Engine That the greater the inward pressure is the less quantity of coals is required to give a certain degree of heat The Rabbet was very tender but the bones were not at all softned no not in the Glass where I had put water but some that had been boiled the day before and put again to be made more ready were found very well softned By this Experiment I saw that although some boiled bones do not seem to be softned at all yet they have got a great preparation towards that though it doth not appear to sense EXPERIM. XI July 13. I took an old male and tame Rabbet which is ordinarily but a pitiful sort of meat I seasoned it and put it into two Glass-pots I kindled six ounces of coals and prest the fire till the drop of water would evaporate in less than 4 seconds the inward pressure was about six times stronger than the ordinary pressure of the Air. The fire being gone out of it self I found the Rabbet very ready and the bones softned and it was as savoury as young Rabbets use to be the Juyce of it turned to a good Gelly so that I think this to be the quantity of fire most fit to boil Rabbets EXPERIM. XII Proprieties August 12. I put
lye in the water and those that would be at the top of them above the water I kindled the fire so as to dry away the drop of water in 5 seconds and the inward pressure ten times stronger than the ordinary pressure of the Air I took away the fire presently and the Vessels being cooled I found all the Beans very soft and no difference between those that had been boiled twice and those that had been but once but those at the top were full of wrinkles and more savoury than those in the bottom which were swelled with water the skin was very soft except a very thin one which was somewhat harder so that it would be needless to take off the skin of such Beans By this Experiment I was more-confirmed that Aliments in this Engine may when they are ready be kept upon the fire a great while without danger Propriety In the above-mentioned Experiment I was careful not to lay upon the rod LM more weight than was necessary to make the inward pressure ten times stronger than the ordinary pressure of the Air so that the Balneum Mariae being pretty hot the great quantity of water was able to lift up the little valve at the top of the Pipe HH and it ran slowly that way till I took off the fire but when the fire was quite out nothing more could get out though the heat was still such as to dry away the drop of water in 5 seconds So it is plain that the remaining water had now room enough in the Engine to expand it self and that such a degree of heat could not make it press stronger than ten ordinary pressures of the Air. Therefore I was desirous to see how large that room ought to be to that end I opened my Engine with so much wariness that I lost no water and having weighed all that I found in it I saw that there had been lost 〈◊〉 or little less because out of eight ounces which I had first put into it I found above seven remaining Therefore we may reckon this amongst the Proprieties of this Engine That if we put into it of the water it can hold and make such a heat as to dry away the drop of water in 5 seconds the inward pressure shall be ten times stronger than the ordinary pressure of the Air. After that same way one may find by experience how much room must be left empty for any other pressure and for any other degree of heat we have a mind to make and that will be necessary to know at Sea as I have said Chap. 2. EXPERIM. XVII July 15. I put some green Pease into two little Glass-pots and poured water into one of them almost enough to cover the Pease into the other I poured no water I pressed the fire till the drop of water would dry away in 4 seconds and the inward pressure was ten times as strong as the ordinary pressure of the Air. I took off the fire and the Vessels being cooled I found the Pease extremely well softned those without water had given juyce almost enough to cover them their colour was of a dark red and their smell and taste had somewhat of burning in the other pot the Pease were green still and had a very good taste but not so high as those without water Having meited some fresh Butter the taste of the Pease without water did not seem to me too strong with such a Sauce I liked them better than the other Yet it will be better not to boil Pease so much these having endured so much heat as would soften bones The Pease which I had put in with the Cods were very soft and good but the inner rinds of the Cods were not at all altered though they had endured so much heat This Experiment seems to prove that water is the best thing to hinder the burning of the Pease but I believe that if many other things were added to fill up the spaces between the Pease it would do as well for that purpose for I have tryed another time that having boiled Goose-berries at the same time in the same pots both without water with this only difference that in one pot the Goose-berries were entire and in the other they were bruised it came to pass that the entire ones had contracted much Empyreume though their glass was much emptier and so the pressure in it could not be so great but those that were bruised and did fill up the pot with their own juyce had no taste of burning Therefore I would advise you for the better success of this Experiment to fill up the spaces with the juyce of other Pease because being already satiated with the taste of the Pease it will not rob those new ones that are to be boiled in it This Experiment shews that many digestions may be perfected a great deal better in this Engine where we may fill up the Glass than in the ordinary way where much room must be left empty It might also suggest good thoughts about the nature of the Empyreume but it is better to stay for further tryals CHAP. III. Experiments for Voyages at Sea EXPERIM. I. THE greatest inconveniency in long Voyages at Sea comes according to the most common opinion from the Victuals which having been kept falted a great while have lost their volatile and spirituous parts so that the remaining gross and terrestrial ones are apt to make a gross and terrestrial blood which causeth the Scurvy Therefore it is likely that Gellies being made of volatile parts and easie to be digested would be apt to correct that defect of the salt meat but they use to be so dear and so hard to be made that it is rare to get any at Sea this made me believe that it would be a good thing to find a way how to make them every where easie and cheap Therefore June 18. I took Beef-bones that had never been boiled but kept dry a long time and of the hardest part of the Leg these being put into a little Glass-pot with water I included in the Engine together with another little Glass-pot full with bones and water too but in this the bones were ribs and had been boiled already Having prest the fire till the drop of water would dry away in 3 seconds and ten pressures I took off the fire and the Vessels being cooled I found very good Gelly in both my pots but that which was made out of ribs had a kind of a reddish colour which I believe might proceed from the medullar part the other Gelly was without taste or colour like Harts-horn Gelly therefore I do not see any reason why it should not have the same effect and I may say that having seasoned it with Sugar and Juyce of Lemmon I did eat it with as much pleasure and found it as stomachical as if it had been Gelly of Harts-horn Though this Experiment be most necessary at Sea yet it will be very useful
upon Land too Gellies being every where good for several diseases it will be very convenient to be able to make easily for one penny more than we could buy for a shilling EXPERIM. II. I filled again a Glass-pot with water and some of the hardest bones of a Leg of Beef in another Glass-pot I put the bones of a Breast of Mutton that had been boiled already but not softned Having shut them both in the same Frame so that one was no more constrained than the other and having inclosed them in Balneo Mariae I prest the fire till the drop of water would dry away in 9 seconds but then it fell out that the little Valve P not holding because I had put leather to it all the water from the Balneum Mariae got out with so much violence that I was surprised at it yet this lasted about a minute because the aperture was but little No question but at the same time the water in the Pots did expand it self too and run over for I found them much emptied yet they did differ from one another because the liquor with Mutton-bones turned to a strong Gelly though the bones were not softned but in some extreme parts and that Gelly did weigh but 〈◊〉 less than the water I had put to it in the other Pot the bones were not softned at all the liquor would never congeal only it was a little thicker and there had been above ¾ of it spilt though this Pot had its brims a great deal higher than the other This Experiment made me believe 1. That it would be better still to provide Mutton-bones than Beef-bones 2. That it would be to no purpose to undertake after the ordinary way to make Beef-bones gelly because it requireth such a great heat and so much water would be lost by evaporation 3. That Gelly is of a contexture much more difficult to be evaporated than ordinary water EXPERIM. III. June 23. I put the same Beef-bones into the same Pot with new water and the weight of the water was as much again as that of the bones in the other Pot I put Gristles with double their weight of water too Having increased the fire till the drop of water would dry away in 3 seconds and the inward pressure ten times stronger than the ordinary pressure of the Air I kept the fire so for four or five minutes more and then I took it off and the Vessels being cooled I found the bones pretty brittle but the liquor was not thick enough to be called Gelly yet I believe if that which had been spent in the former boiling had been there still the Gelly had been strong enough The Grisles in the other Pot were almost quite melted down and were turned to a strong Gelly from the bottom of the Pot to the middle of it but above that the liquor was no thicker than in the other Pot. This Experiment made me think 1. That one pound of Beef-bones might afford about two pounds of Gelly 2. That it would be better to provide Grisles because they are wholly glutinous and will dissolve in water but because water is not so heavy the Grisles will sink and stay in the bottom and imbibe just as much water as is necessary to make a Gelly 3. That it is the Cement that unites the parts of the bones which is dissolved in the water to make it a Gelly since after that the bones remain brittle EXPERIM. IV. June 29. I put more bones into two little Glass-pots than was necessary to congeal the water they were in one was with Beef-bones the other with Mutton-bones I increased the fire till the drop of water did dry away in 3 seconds with the inward pressure ten times stronger than the ordinary pressure of the Air. I kept the fire to that degree about a quarter of an hour and then took off but part of it leaving the rest to keep the heat yet longer The Vessels being cooled I found very good Broth without Empyreume in both the pots but it did not turn to gelly which I think could not proceed but from too much boiling since in the former Experiments with less bones and less heat I had got a strong Gelly From this Experiment it appears that the degree of heat is much to be observed to make a great quantity of Gelly and that it is not enough to keep it from burning for it might for all that be much over-done Now that degree of heat which is best of all cannot be found but by several Experiments EXPERIM. V. June 29. I put Beef-bones into one of the little Glass-pots with an equal weight of water into the other I put as much Ivory as I could with water to fill up the chinks I blew up the fire till the drop of water would dry away in 6 seconds with the inward pressure twelve times as great as the ordinary pressure of the Air then I took off the fire as fast as I could and the Vessels being cooled I found that the Pot with Ivory had been broken because the Ivory that was crowded in it swelling by humidity and heat had been stronger than the Pot the Ivory was grown brittle In the other Pot the bones were not softned yet but in some Apophyses the liquor was not congealed neither except in the bottom but the next day being a little cooler I found it turned all to a Gelly and I poured it upon several glass Plates that it might dry the next day July 1. though it had been evaporating 24 hours I found it melted again because as I think the weather was a little warmer I used it to glue a broken glass which did since that time hold very well and can be washed as well as if it had never been broken From this Experiment I judged 1. That the heat had been too weak as in the foregoing it had been too strong and so to bring the bones to a good gelly the fire should be augmented as in Exper. 1. or thereabout 2. I was more fully perswaded that it is the glue of the bones which is dissolved to make gelly 3. I found that very few glutinous parts are sufficient to congeal much water for though this had been congealed in Summer-time in a Garret yet when it was dryed I had so small a quantity of glue remaining that I was surprised at it 4. I found that a very little heat is enough to hinder these congelations and therefore in all appearance the quantity of gelly would be much greater in Winter than in Summer-time from the same quantity of Materials 5. That such Congelations are very differing from those that are made meerly by cold since the Ice swims at the top but Gelly sinks to the bottom of the water To use the glue here spoken of it must be kept clean and when we have occasion to use it we must dissolve some of it with three or four drops of clean water to wet the brims
in the pot containing those Goose-berries that had never been fermented but in the other pot there was no change at all so that it seems the Fermentation before boiling is a remedy against corruption I took the Fruit that grew musty and having exactly filled a lesser glass with it I fastned a good cover to it with a Screw this prevented further corruption and that same Fruit in five or six days began to ferment and the juyce ran over though the Screw prest the cover pretty hard August 30. I opened that same glass whose cover was fastned with a Screw and having put some of the Fruit and Juyce into a little glass-pot then having shut all in the Engine I increased the fire till the drop of water dried away in 6 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air. I took off the fire and the Vessels being cooled I found the Goose-berries had by boiling again lost much of their sweetness but their taste was very pleasing it may be many people would like it better than before having put some of their Juyce into a glass and some of the Juyce that had not been boiled again into another glass I put them both together in Vacuo and I saw that the Juyce twice boiled had given over fermenting because it did not bubble but the other did mightily From all I have said in this Experiment I believe I may conclude 1. That if we keep Fruit as I have said in the beginning that is to say if we let them ferment softly in Vessels well stopt we may at any time make with them very good Sweet-meats at a cheap rate by the help of the Engine that will soften the Fruit and keep the Spirits from evaporating 2. There will be less danger of growing musty when the Fruit hath been boiled so during the Fermentation 3. If any mustiness appears we may hinder it by filling up the Vessels and fastning the cover with a Screw 4. If the Fermentation begins again we may stop it by a new boiling Yet this Experiment ought to be continued some time longer before we can be assured how far it will go I do not here describe the way how to fasten a cover to a glass with a Screw since it is the same that hath been said in Chap. 1. for the Pot GG and people that would make a great Trade of that kind might instead of glasses make use of high earthen pots EXPERIM. IV. August 17 18. I repeated the same Experiment but instead of Goose-berries I made use of Plums I boiled some of them three several times but I learned nothing worth relating only that Plums after they are boiled fermenting with ½ or ¼ of Sugar will taste like Wine stronger and more pleasing than Goose-berries and I do not question but many men will approve of this pleasant relish beyond that of most Sweet-meats I did also observe that when I distilled them in the manner described Chap. 6. Exper. 3 they yielded juyce in a greater quantity and thicker than when boiled as the Goose-berries before-mentioned were CHAP. V. Experiments to make Drinks EXPERIM. I. JVly 22. I included two or three weeks ago some ripe Goose-berries in a great glass and filled all the interstices with water and Sugar to day seeing the Fruit did ferment apace I took out some with the liquor and filled therewith ⅘ of a little glass-pot then I made use of some of this liquor alone to fill another glass-pot wherein I had put some fresh Goose-berries unfermented having included these two pots in the same frame and in the same Engine I advanced the fire till the drop of water would dry away in 2 seconds and kept it so for a while the inward pressure was ten times stronger than the ordinary pressure of the Air. The Vessels being cooled I found the pot containing the fermented Goose-berries to be half empty and mightily burnt but the Vessel containing the fresh Goose-berries was scarce at all the emptier though there were in it a good deal of fermented liquor which had no taste of burning From this Experiment I concluded that when Wine is made so by infusing fruit in water and Sugar there is much more strength in the fruit than in the liquor so that the fruit by fermenting comes to be near as apt to rarifie as Spirit of Wine it self see Chap. 6. Exper. 2. Therefore I though if I did make Wine with fruit alone without water it would be mighty strong but because the juyce of Goose-berries and several other Fruits are too thick to make Wine withal unless they be boiled I think that this screwed Engine is very necessary to boil these Juyces seeing we can perform it without water and without evaporating the most subtile parts therefore I made the following Experiment EXPERIM. II. July 25. I put ripe Goose-berries into a Pewter-pot and having inclosed it in the Engine I continued the fire till a drop of water would dry away in 3 seconds with an inward pressure ten times stronger than the ordinary pressure of the Air I presently took off the fire and the Vessels being cooled I found that the Goose-berries had yielded a very red juyce and that in the places where the Goose-berries had been burst next to the Pewter pot they had acquired a very fine purple Violet colour I put this morning some of the same ripe Goose-berries with water and Sugar into a glass Vessel well stopt and afterwards I put some of the Goose-berries newly taken out of the Engine into another glass with some of their Juyce and ¼ of Sugar that I might see which of them would ferment sooner and better August 2. Two or three days ago I saw the Goose-berries ferment in both glasses much alike and to day having taken some of the Juyce out of the two glasses I put them severally into two Vials and then I put them both together in Vacuo where I observed according to my expectation that the Juyce of those Goose-berries that had been boiled was much more like the nature of Wine than the liquor of the other glass for that bubbled more and its taste was more pungent and spirituous August 3. I separated the boiled Goose-berries from their Juyce and squeezed them that they might yield more I put all that Juyce into a Bottle which I have kept ever since that is near six weeks For two or three days in the beginning that liquor fermented mightily threw out the Cork and ran over though it was not 〈◊〉 full but since that time it hath been much abated and now its taste is very good and pungent yet it doth ferment still several bubbles arising in it and it is not clarified this makes me believe that such Wine may be kept for a great while and that it is to be feared rather that it will be too long a making than that it will grow four too soon I put the remainder of the
squeezed Goose-berries into another Glass with water and a little Sugar this in less than 24 hours began to ferment very violently and in a fortnight the liquor was pretty well clarified and good to drink but not so strong as that without water and I believe also it would have grown four in a short time This Experiment was made by guess and without Scales but I guest the fruit to have been about ½ of the weight of the water and the Sugar 〈◊〉 From this Experiment we see that the same fruit by means of this Engine may afford two sorts of Wine the one to keep long and the other to drink quickly EXPERIM. III. August 5. I took some of the Juyce of the Goose-berries above-mentioned in the time it did ferment most briskly and having put it into a little glass-pot and then in the Engine I continued the fire till the drop of water would dry away in 10 seconds with an inward pressure three times stronger than the ordinary pressure of the Air. I found that the liquor had got a taste near to that they call in France raisiné and it was pleasing to drink and apt to quench thirst Then that I might know whether the liquor had been much altered by boiling in the Engine I put some of it into a little glass and took some also out of the great Bottle that was a fermenting and having put it into another glass I included them both at the same time in Vacuo and found that the liquor which I had set upon the fire during its fermentation did not bubble so much as common water would do but the other liquor did at the very first suction rise all into bubbles From this Experiment I guess 1. That by boiling a Liquor whilst it ferments we may quickly take away the ill quality it hath to generate winds and cause pains in the Belly 2. That such a liquor would not hurt the Head neither as Wine doth because the Spirits are not yet quite so loose as they are in Wine and this appears because the Wine boils in some measure in Vacuo Boyliano but this liquor doth hardly yield any little bubbles 3. That such a liquor would not easily dye since the Spirits can so hardly extricate themselves And lastly I am very apt to believe that it would be a good nourishing and strengthning Drink since Bread is reckoned to be the staff of life which is put into the Oven even during its fermentation yet we must expect further Experiments before we can have any certainty of it in the mean time we may be sure that such drink may be got ready pretty soon EXPERIM. IV. August 17. I took Juyce of Plums distilled after the manner to be described Chap. 6. Exper. 3. and because it was thicker than that which is drawn without distilling for the Juyce which remains in the heat with the fruit is thereby continually attenuated I thought I should use more heat to attenuate the same therefore having shut it after the ordinary way I continued the fire till the drop of water would dry away in less than 2 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air I took away the fire and the Vessels being cooled I found contrary to my expectation that the Juyce was become almost all solid from the top to the bottom of the pot and that it was turned into a black stuff much burnt which could easily be powdered between ones fingers yet there were many cavities full with a very fluid liquor which had such an acrimony that the Tongue could hardly endure it so that the heat did work upon that Juyce almost the same effect as the Runnet doth upon Milk I have kept for two months together some of the same distilled Juyce of Plums and I found that it was not at all grown hard as that which had been in such a great heat was but it hath fermented very little in comparison with those that are more sluid This Experiment shews that the degree of heat is to be well observed in making Drink not to give too much nor too little and that distillations of Juyces may indeed prove very good to make clear Cakes Gellies Syrups c. but for Drinks ordinary boiling as I have said of Goose-berries will do better yet in time it may be such thick Juyces will make stronger Wines than thinner ones but I am afraid that will require many years EXPERIM. V. August 17 18 c. I kept Juyces of Plums to make the same Experiments as I have said of Goose berries but I think it needless to give the particulars of them because I learnt nothing new by them but that Damsons if they be not too ripe nor over-boiled will make Wine much stronger than Goose-berries and that having mingled a little Juyce that was a fermenting with a Bottle of Juyce newly drawn this mixture did like a Ferment hasten the fermentation in the said Bottle CHAP. VI. Experiments for Chymists EXPERIM. I. JVly 13. Dr. Slare Fellow of the Royal Society had a mind to try whether the Engine could not be useful to draw quickly the most stubborn Tinctures in Chymistry therefore we put into a little glass pot Salt of Tartar with rectified Spirit of Wine into another pot we put Amber with some of the same Spirit of Wine We continued the fire till the drop of water would dry away in 3 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air and then we did put it out presently The Vessels being cooled we found in the first pot that the tincture of Tartar was as strong as it could have been made in a months time after the ordinary way and its taste was lixivious in the other pot the tincture of Amber was a great deal stronger than usually it is EXPERIM. II. July 15. Dr. Slare had also a mind to make a tryal of the tincture of Antimony the fire was lighted by 10 〈◊〉 of the clock in the morning 1 continued it till the drop of water would dry away in 2 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air I took off some part of the fire so that the heat being diminished the drop of water did evaporate but in 3 seconds and nothing could get out of the Engine I kept the fire much about that same strength till 1 in the afternoon then I left it till about three of the clock at which time I found the Vessels much cooled and the fire almost out I lighted it again so that the drop of water would evaporate in 1 1 ◠second and then I saw again something get out through the little Valve P and I took off some of the fire till the drop of water would dry away but in 2 seconds and then the Engine was very tite again I let the fire go out of it self and found that the Vinegar had
Cochenille would give all its tincture without being grinded therefore he put three grains of Cochenille very entire into a glass pot with three ounces and half of water and at the same time he put into another pot some coarse Cochenille that is sold eight times cheaper than the other and therefore he put eight times greater quantity of it in proportion to the water Having increased the fire as in the former tryal with rubia tinctorum we found in the first glass that one of the grains of Cochenille had been quite dissolved and that the two remaining had lost all their colour and were turned black the liquor was of a fine red colour but in the second pot the tincture was stronger and deeper From this Experiment it appears that by the help of this Engine one may save all the labour of grinding the Cochenille and all the wasting of it and perhaps coarse Cochenille will give much more tincture than usually it doth I made a tryal with these Liquors to know whether the Pneumatick Engine would help Tinctures to penetrate better into the cloth I put a piece of cloth into one of the liquors and having set it so in Vacuo I saw according to my expectation that a great many bubbles of Air got out of the cloth so that I was in great hopes that the tincture getting into the place of that Air would penetrate every where yet having let in the Air again and exprest the humidity from the cloth I found that all the colour was gone too from whence I concluded that it is not enough to have the colour insinuate between the hairs of the cloth but that it must get into the hairs themselves and this cannot be done unless all the little particles every hair is made of be rarified and expanded by heat which is much more powerful for that than any Tacuum can be EXPERIM. IV. August 18. I put two pieces of cloth into two glass pots to one of them I added some tincture of coarse Cochenille and to the other Juvce of Prunes distilled after the manner described Chap. 6. Exper. 3. I prest the fire till the drop of water would dry away in 42 seconds with an inward pressure six times stronger than the ordinary pressure of the Air then I took off the sire quickly for fear the cloth should be spoiled the Vessels being cooled I found both the pieces of cloth good still and well dy'd the Juyce of Prunes having penetrated as well as the tincture of Cochenille but the tincture of it was of a deeper red and nearer to a brown colour the Juyce it self was much altered for it was Violet before it was grown also much more liquid and watry From this Experiment it appears that this Engine keeping things for a great while in a great heat without damage and hindring the most subtile parts from getting away as usually they do may be sit to insinuate into cloth such liquors as are reckoned to be too thick and glutinous as the Juyce of Plums is because for dying there is no need of good taste Mr. Mayre thinks there would be no need of an inward pot and so I believe the aperture of the outward Engine might be left lesser than the cavity as you may see Fig. 6. Yet if they would dye cloth in it the aperture HH should be left wide enough to convey the cloth into the cavity AA and this Engine should also hang in Aequilibrio by its Appendices CC for the conveniency of filling and emptying the same CHAP. VIII Experiments upon barder Bodies as Amber Ivory c. IHave made other Experiments upon harder bodies as Amber Ivory Cow's horn Tortoise-shells but because I have found nothing yet that may be brought to use I will not be tedious in relating the Particulars of those Experiments therefore I shall only set down some few observations which they afforded 1. Amber could never be melted whatever degree of heat I made use of though I filled the Engine with Pitch and Sand instead of water and I prest the cover with eight Screws instead of two I could indeed separate several substances from it as Balsam Fumes and Terrestreities but that cannot be called melted Amber since it hath-lost several proprieties belonging to Amber for if we dissolve these substances with Spirit of Turpentine they cannot be brought to any considerable hardness by evaporating the Spirit and an indifferent heat will soften them again 2. Mr. Boyle having given me some Copal Gum to try what it would do I found indeed that it could be melted without being much altered but when I would apply the same to facilitate the melting of Amber I found that it would not do I would for the same purpose make use of Gum Tragacanth Mastich and Rosin but it was all in vain so that I believe one may be sure that the melting of Amber requires a stronger and quicker heat than this Engine can give 3. Though Cows horn seems to be a more glutinous matter than bones are I could never make any gelly or glue with it though I have put the same over and over again in the Engine upon the fire even four times successively 4. I could never make Ivory soft and glutinous though I have boiled it several ways and in several Menstruums as Grease Oyl Beer and Water I could draw a fine and transparent Gelly from it but the body remained brittle 5. Tortoise-shell cannot be softned by boiling in Oyl but in Spirit of Wine it swells and hath a great many cavities like a Sponge 6. Cows horn and Tortoise-shell having been with water exposed to a heat that drys away the drop of water in 3 seconds with an inward pressure twelve times stronger than the ordinary pressure of the Air they come to be so soft that they do not grow hard again but in three or four days time and this perhaps might be of some use and give more conveniency to work those Materials than when they are heated only after the ordinary way but I must confess that they will afterwards be more brittle than before and I have seen once two pieces of Tortoise-shell that had been by boiling so well glued to one another that after they were hardned again they would rather break in other places than be separated CHAP. IX A Calculation of the price that a good big Engi ne may come to and of the profit it may afford BEcause people are loth to meddle with new Inventions lest the expence should be greater than the profit to be got by them I will subjoyn here a calculation of the price which a good Engine may come to and of the profit that may be got by it I have been at an Iron-mongers house and there I caused a cast Iron Pipe to be weighed This being six inches in Diameter and two foot long and without doubt strong enough to endure an inward pressure twenty times stronger than the ordinary pressure of the Air
This Pipe I say did weigh but 57 pounds so that such another Pipe 12 inches in Diameter and as strong proportionably to its bigness will weight but about 228 pounds But let a covered Vessel weigh 250 yet it will not come to 48 shillings seeing the Merchants can with good profit afford such Metal at two pence half penny a pound Now if the cover and the Vessel were ground to one another and that in a Country where Work-men are cheap the grinding will scarce come to two shillings Then the Iron pieces DD with four Screws lest two should not do enough and the Iron rod LM may be afforded much under five shillings especially if made in the Country and in numbers Five shillings would also be a great deal too much for setting the Pipe HH and sitting a Valve to it The inward Pot GG of cast Iron or glass or stone-pot might also be got under 20 shillings strong enough and big enough to hold 80 pounds of water I confess it would be a hard matter to make a Glass so big but instead of one they may make three or four to be set in the same Frame one above the other So that we may be sure that a Merchant may with good profit afford such Engines ready in good condition at 4 l. sterling apiece Now such an Engine is able to make above 50 pounds of the Gelly at a time and may do the same quantity at least twice in 24 hours for I have tryed that my great Engine which is 6 inches in diameter may in less than an hours time be heated enough to make Gelly of Bones therefore one may make 100 pounds of Gelly every day Now in Paris where people constantly keep Gelly ready to sell the price of it is 20 pence a pound but in London where they make none unless it be bespoken Apothecaries use to sell it at 2 shillings a pound therefore it would be a very good thing for the Publick if any one would sell Gellies for a groat a pound yet at that price the aforesaid Engine would make Gelly for above 33 shillings every day The fire will not come to six pence and the bones with some Harts-horn might be got cheap enough too since it is not necessary to shave them for this Engine and a little Sugar serves for Gellies yet let the expence come to 13 shillings a day there will be still 20 shillings profit for the Owner of the Engine and so in four days time he will be fully requited for his first expence and one man alone may at the same time keep five or six such Engines at work for several uses whereof some perhaps will prove more profitable than the making of Gellies Therefore we must not question but those that will set upon such things may make their own profit very well and at the same time do a great service to the Publick I have not therefore thought it right in a thing of so general use that a man by virtue of a Patent should hinder other people from working that may perhaps have more skill in doing things good and cheap and I have instructed Mr. Mayor a Founder in Old Bedlam how to make these Engines of cast Brass so that any body may see them and buy them of him POSTSCRIPT DOctor Edm. King Fellow of the Royal Society having got one of these Engines for a greater security and conveniency caused the rod LM to be fitted in L with a Joynt so that it must always fall upon the Pipe HH and there is no danger that the Valve P may slip off and spoil the Operation he hath also caused a Brick Furnace to be built on purpose so that I have lately tryed whether by that means the expence of coals would be less than in my Chimney-corner see pag. 6. but I have found contrary to my expectation that the expence is much greater in his Furnance the reason of which probably is because in his Furnace the coals did not at all touch the Engine but remained at a little distance below as in ordinary Sand-Furnaces the coals do not touch the Pot but in my Chimney the coals touch the Engine almost all along and thereby may the better heat it It is therefore likely that it would be better to build Furnaces so as to have the coals touch the Engine all along one side It would be better also to have them made of Iron plates because a Brick Furnace requires much fire to be throughly heated unless it be kept at work constantly Mean while the Doctor hath made several Experiments with his Engine having this conveniency that there is no need of blowing the fire Besides many good dishes of Meat and Fish he hath prepared several Medicines and found that in this Engine the Operation may be performed in less than the tenth part of the time that is required in his other Furnaces and yet some of them are much stronger than ordinary We have seen that Harts-horn in Winter time being boiled with twelve times as much water will turn it all to a Gelly so do the bones with above four times as much water which is at least as much again as I had found in Summer time Vpon this occasion I will mention two other Particulars which do not succeed in cold as in hot weather The first is the Fermentation of Bones spoken of Chap. 3. Exp. 8. which is not so well performed in Winter The second is the quantity of fire required in such Operations for I have found by my Engine that Mutton may be very well drest and the bones softned with five ounces of coals in Summer time but in Winter the same effect cannot be produced with less than six ounces and half We have seen that it is not necessary to put in the Engine all the water to be congealed but putting equal weight of bones and water after the Operation your water being mingled with three times as much fresh water will turn it all to a Gelly so the Gelly to be made with an Engine and therefore the profit to be got by it is much greater than I have said Chap. 9. I have found that an old Hat very bad and loosely made being imbibed with Gelly of Bones is become very firm and stiff so that it is likely if such Liquor should be used in making Hats they would be extraordinary good The Doctor 's Engine having already given occasion to these Experiments I doubt not but when the thing is made common a great many more Uses of it will be found in a short time FINIS
exactly ground to it and pressed upon it with a Screw as you see in the Figure is to be included in the Cylinders AA BB. with water all round about it TO use this Engine with conveniency and ease it ought to be fitted in a Furnace built on purpose for it and should go in as far as the Appendices CC so the fire being underneath and the Screws FF well fastned you may boil your meat as long as you please without danger of wasting it by the exhalation of the volatile parts It is to be noted that such a long and slender shape is better than any other for such an Engine because it may be kept shut with less strength for it is well known that the wider an aperture is the more strength is required to keep the cover from being lifted up by the inward pressure It is to be noted also that the cover BB must have some depth that being filled with water it may always keep some moisture in a circular piece of paper which is to be put in the joynt II for the two Cylinders can never be ground to one another so exactly as to keep in Liquors when highly comprest unless there be some paper put between them and that paper cannot stop it exactly neither unless it be wet yet the depth of the said cover BB ought to be but little that the Engine being almost all closed in the Furnace it may the better receive and keep the heat This Engine is without doubt simple enough and easie enough to be kept in order but the mischief is that it is much more troublesom to look into it than into ordinary pots and because it doth more or less effect according as the included water is more or less comprest and according as the heat also is greater or less it may sometimes happen that you will draw your meat before it is ready enough and sometimes too you may burn it It was therefore necessary to find out some way how to know both the quantity of the inward pressure and the degree of heat To know the Quantity of the inward Pressure You must have a little pipe open at both ends as HH this being soddered to a hole in the cover BB is to be stopt at the top with a little valve P exactly ground to it and fitted also with a paper between This must be kept down with an Iron rod LM one end of which must be put into an Iron staple LG fastned to the bars EE and the other end kept down by a weight N to be hung upon it nearer or further from the valve according as you would have it keep it less or more strongly down upon the end of the pipe to resist the less or greater pressure from within much after the manner as a weight is hung upon an ordinary Roman balance or Stilyard To prevent the drying of the paper of this valve I take a little pipe OO tyed about with hemp and thrust it down into the pipe HH so that one end reacheth pretty far into the water in the Engine whence it comes to pass that if some of the said water be lost the inward pressure will nevertheless drive up water through the said pipe OO against the valve P which makes the said valve more exact and more fit to shew whether any thing gets out that way The pipe HH must be but slender that it may be kept shut by a little weight in the Engines I have hitherto imployed this pipe is about â…• of an inch over so that its aperture to an aperture 1 inch over is as 4 to 25 therefore being more than six times less it may be kept shut with a weight more than six times lighter too Now according to the Experiments of Mr. Boyle in his continuation of Physico-mechanical Experiments the ordinary pressure of the Air against a hole 1 inch over is about 12 pounds and therefore it is about 2 pounds against the aperture of the said pipe HH The rod LM is 12 inches long and the distance from L to P is 1 inch so that 1 pound weight hanging at M presseth as much upon the valve P as 12 pounds could do if directly laid upon the said valve and so it cannot be lifted up unless the inward pressure be six times stronger than the ordinary pressure of the Air. Therefore when there is one pound weight hanging in M and yet the water gets out under the valve one may conclude that the inward pressure is about eight times stronger than the ordinary pressure of the Air because it lifts up not only the weight N which is equal to 6 but also the rod LM which I have found by tryal equal to 4 pounds or two pressures against the valve and so by increasing or lessening the weight or by removing it from one place to another one may always know near enough how strong the inward pressure is The same Pipe HH is also very commodious to sill up the Engine with water after it is shut by the Screws and the pipe OO is not to be put in till the Engine be perfectly filled with water by the pipe HH To know the Degree of Heat I wish I had been able to make a Thermometer divided as it should be to shew precisely by how much the heat is increased or diminished and I believe by that means comparing the several degrees of heat with the quantity of the effect thereby produced one might discover several things about the Nature both of heat and of the Materials wrought upon but for want of time and other necessaries for that design I have instead of it used another way very easie and yet exact enough for all the uses here spoken of I hang a weight to a thread about three foot long so that every swing makes about a second and I let fall a drop of water into a little cavity made for that purpose at the top of it and I tell how many times the hanging weight will move to and fro before the drop of water is quite evaporated and I take care that the place where I put the drop may be clean because a little grease will considerably hinder its evaporating So being able to know the degrees both of heat and pressure in the Engine one may easily order it so as to do the effect just as desired if it hath but once been tryed how powerfully it works For you need but take the quantity of coals found out by Experience to be the most convenient set it in the Furnace under the Engine leave the doors and the registers of your Furnace open till the heat is come to your intended degree then you are to shut both the doors and the registers that the fire may be choaked and so let your Vessels cool but you must also have laid upon the rod LM as much weight as is necessary to make the intended inward pressure and you may be sure that by always keeping